1. Field of the Invention
The invention relates to a chronograph having a chronograph drive by means of which, when a first actuating element is actuated manually, a chronograph-hand stem of a chronograph hand stem of a chronograph hand can be driven in rotation. A rattrapante-hand stem, coaxial with the chronograph-hand stem, of a rattrapante hand can be driven in an overlapping manner with the chronograph hand, a seconds heart cam for resetting the chronograph hand being arranged on the chronograph-hand stem. The chronograph-hand stem and rattrapante-hand stem can be connected to one another in a rotationally fixed manner by a rattrapante hear cam of a force-fitting coupling. A rattrapante wheel arranged on the rattrapante-hand stem can be encompassed under striping prestressing by the gripper arms of a rattrapante gripper and can be blocked against rotation by a friction or form fit. A switching element can be moved by manual actuation of a second actuating element between a blocking position and an unblocking position and by means of which the gripper arms can be lifted off from the rattrapante wheel, out of their rotation-blocking position.
2. Description of the Related Art
Such a chronograph is known from DE 42 09 580 C2. It is possible in the case of this known chronograph, following start-up, by actuation of the first actuating element, for the chronograph hand and the rattrapante hand to be stopped again together. It is also possible, by means of the second actuating element, to stop just the rattrapante hand, while the chronograph hand continues running. It is thus possible to measure time intervals within a minute. If the second actuating element is actuated again, the rattrapante hand jumps to the position of the continuing chronograph hand and continues running therewith, and is ready for a further time interval to be measured anew. The measurement of time intervals can be repeated as often as desired. If it is also desired to stop the chronograph hand, the first actuating element has to be actuated again. There are thus two states for the stationary hands. Either the two hands are located one above the other or each hand has a dedicated position.